Tinted perspex visors used to be available and I have some on my Roadster. I have fitted the brackets upside down and the visors are fixed in the up position.
For a while, Mini tinted visors were available on e-bay. They might still be. For about £35 you get a pair with four brackets. These visors are too narrow for the Morgan screen stubs, but it's easy to get laser cut tinted perspex on line.
